BIOLOGICAL CHARACTERISTIC OF PATHOGENIC FUNGUS CAUSING ANTHRACNOSE OF LOQUAT FRUIT

Effects of temperature, pH, light, carbon, nitrogen sources and moisture on mycelial growth, sporulation and conidial germination of anthracnose fungus (Colletotrichum acutatum Simmonds) that affects loquat (Eriobotrya japonica) was investigated. For the mycelia growth of Colletotrichum acutatum, a temperature range was determined to be 6-34°C with the optimum temperature of 26-28°C while the pH range was 3-12 with the optimum pH value of 6. For sporulation, the range of temperatures was 6-34°C with the optimum being 18-26°C and the range of pHs were 3-12 with the optimum being 9-10. For the conidial germination, the temperature range was 6-34°C with the optimum temperature of 20-26°C and the pH range was 3-11 with the optimum ph value of 6. When the relative humidity (RH) reached 100%, the percentage of conidial germination was the highest. However, it was found that the conidia did not germinate when the RH was below 90%. Sucrose, maltose or D-fructose promoted conidial germination. However, ammonium phosphate inhibited the conidial germination. The lethal temperature for the spores of Colletotrichum acutatum was determined to be 5 min at 50°C or 2 min at 55°C while the lethal temperature for the mycelium was 10 min at 50°C or 5 min at 55°C.